I think it's pretty safe that there has never been a sci-fi shooter franchise that has impacted popular culture like Microsoft's Halo series.

Believe it or not, the first Halo title, Combat Evolved, was released on the original Xbox back in 2001. Someone who was born the day that Halo: Combat Evolved was released is only three or four years away from getting their driver's license. Feel old yet? Don't worry about it, because these Halo-inspired finds from the creative minds of Sci-Fi shooter fans are guaranteed to give you a plasma grenade-infused mood boost.